1. Field of the Invention
The present invention relates to the field of shock-absorbing devices. More particularly the present invention relates to the field of shock absorbing suspension systems for bicycles and motorcycles.
2. Description of the Prior Art
Shock-absorbing devices have been long utilized in bicycles, motorcycles and like vehicles. Particularly, shock-absorbing suspension systems have been used in the front and rear fork assemblies and other body parts, such as the seat support structure, of bicycles and motorcycles.
Shock-absorbing suspension systems incorporated in the body frames of bicycles and motorcycles include primarily three basic models: the mechanic model which utilizes metal coil springs, the hydraulic model which utilizes oil-dampers, and the elastomer model which utilizes resilient rubber elastomers. The present invention is a new development of the elastomer model.
The following six (6) prior art patents are found to be pertinent to the elastomer model of the shock-absorbing suspension systems utilized in the body frame of bicycles and motorcycles:
1. U.S. Pat. No. 2,683,034 issued to Seddon on Jul. 6, 1954 for "Rubber Compression Spring" (hereafter "the '034 Seddon Patent").
2. U.S. Pat. No. 2,683,044 issued to Seddon on Jul. 6, 1954 for "Shock-Absorbing Device" (hereafter "the '044 Seddon Patent").
3. U.S. Pat. No. 2,708,112 issued to Seddon on May 10, 1955 for "Shock Absorbers" (hereafter "the '112 Seddon Patent").
4. U.S. Pat. No. 5,193,832 issued to Wilson et al. on Mar. 16, 1993 for "Suspension for Bicycles" (hereafter "the '832 Wilson Patent").
5. U.S. Pat. No. 5,193,833 issued to Reisinger on Mar. 16, 1993 for "Bicycle Front Suspension, Steering & Braking System" (hereafter "the Reisinger Patent").
6. U.S. Pat. No. 5,269,549 issued to Wilson et al. on Dec. 14, 1993 for "Suspension for Bicycles" (hereafter "the '549 Wilson Patent").
The '034 and '044 Seddon Patents have disclosed a rubber compression device for motorcycle front fork suspension systems. The compression device includes a telescoping system comprised of an outer tube and an inner tube. The inner tube is slidably engaged with the outer tube. A strut is placed inside the outer tube and extends into the inner tube. A set of rubber elastomers are placed between the strut and the inner tube. When the telescoping system is compressed, the strut moves into the inner tube and compresses on the rubber elastomers, which function as shock-absorbers. The set of rubber elastomers are skewered on a skewer rod.
The '112 Seddon Patent has disclosed a shock-absorbing device which also includes a telescoping system. The telescoping system comprises an outer tube and an inner tube slidably engaged with the outer tube. A compression elastomer is placed inside the outer tube between the proximal end of the inner tube and the distal end of the outer tube and skewered on a skewer rod. The distal end of the skewer rod is attached to the distal end of the outer tube, and the proximal end of the skewer rod extends into the proximal end of the inner tube. A rebound elastomer is placed inside the inner tube between the proximal end of the inner and the proximal end of the skewer rod and also skewered on the skewer rod. This arrangement makes the compression elastomer to function as a shock-absorber when the inner tube moves into the outer tube, and the rebound elastomer as a shock-absorber when the inner tube moves out from the outer tube.
The '832 and '549 Wilson Patents have disclosed a suspension system for bicycle front forks. The bicycle front fork has two telescoping legs each utilizing a suspension system. The telescoping suspension system includes an upper tube and a lower strut. A set of elastomers are placed between the upper tube and the lower strut and skewered on a skewer rod. The elastomers function as a shock absorber when the telescoping suspension system is compressed. The '549 Wilson Patent has further disclosed that the end of the skewer rod can have a flange so that when the skewer rod is removed, the elastomers can be held on the skewer rod without falling off.
The Reisinger Patent has disclosed a bicycle front suspension, steering and braking system. The suspension system includes an upper tube and a lower strut slidably engaged with the upper tube. A set of elastomers are placed between the upper tube and the lower strut and separated by a set of solid discs. Each solid disc is placed between adjacent ones of the elastomers and has a top surface perpendicular to its rotational axial. Each elastomer further has a center bore, and each solid disc further has a center protrusion extending along the rotational axis of the disc out from the top surface of the disc and received within the center bore of the adjacent elastomer. This feature is designed to limit the ultimate compression, or in the word of the industry, to prevent "bottoming out", of the suspension system, because the protrusions of all the disks function as a solid rod between the upper tube and the lower strut when the telescoping suspension system is fully compressed.
In modern bicycles and motorcycles, it is highly desirable for the individual riders to have the ability to modify the configuration of the elastomers to adjust the compressibility of the shock-absorbing devices. Earlier prior art devices do not provide this flexibility. For example, in the '034, '044 and '112 Seddon Patents, the configuration of the elastomers are fixed by the manufacturer and individual riders cannot modify the configurations of the elastomers without completely disassembling the telescoping suspension system.
Recent prior art devices are designed and constructed to provide the flexibility for the individual riders to modify the configuration of the set of the elastomers to adjust the compressibility of the shock-absorbing devices. For example, in the Reisinger Patent, a rider may theoretically modify the configuration of the elastomers by opening the top cap of the telescoping suspension system, taking the elastomers out and replacing part or all of them with other elastomers which have different compressibility. However, this cannot be easily done because the elastomers in the Reisinger Patent are disconnected to each other and a rider has to place the bicycle upside-down to take the elastomers out of the tube.
The '832 and '549 Wilson Patents have utilized a removable skewer rod for interconnecting the elastomers to avoid the problem that a rider has to turn the bicycle upside-down to remove the elastomers out of the tube. All the elastomers are skewered on the skewer rod, which is attached to the top cap of the telescope suspension assembly. A rider can open the top cap and readily remove the skewer with all the elastomers skewered thereon. However, this skewer design sometimes makes replacement of the elastomers a time consuming and laborious process. For example, a typical elastomer set includes six (6) elastomers, as shown in the '832 and '549 Wilson Patents. If a rider wants to replace the top elastomer, the rider has to taken all five lower elastomers off the skewer rod before the top elastomer can be replaced, and after the replacement of the top elastomer, all these five lower elastomers have to be placed back onto the skewer rod.
Therefore, it is always desirable to design and construct a new shock-absorbing suspension system for bicycles and motorcycles which can eliminate the above-mentioned disadvantages in the prior art devices, while still providing the rider with all the desired functions and features.